1. Field of the Invention
The present invention relates to compositions and methods for improving insulin sensitivity. Particularly, the present invention provides methods for improving insulin sensitivity by using a polysaccharide isolated from Ganoderma lucidum as well as methods for preparing the polysaccharide.
2. The Prior Art
Type 2 diabetes mellitus is a disease characterized by a failure to regulate blood glucose levels. In the long term, this condition may lead to several complications, including cardiovascular disease, eye damage, foot ulcers, kidney failure, and stroke. The high prevalence of diabetes is currently a major threat to public health, with an estimated 387 million diabetic people worldwide. As a result, prevention of diabetes represents a major challenge for modern societies.
In early stage type 2 diabetes, peripheral tissues such as the liver, muscles, and fat tissues show reduced sensitivity to insulin. At this stage, a number of treatments can be used to stabilize blood glucose levels, including diet monitoring, regular exercise, and medications. Metformin is a synthetic drug that decreases hyperglycemia by suppressing glucose production by the liver. In addition, this drug increases sensitivity to insulin in peripheral tissues and decreases absorption of glucose by the intestinal tract. However, metformin and other anti-diabetic medications produce side-effects, including diarrhea and other gastric disorders, kidney dysfunction, liver disease, nausea, skin rash, and urinary tract infections, which may limit treatment compliance and efficacy.
In view of the growing incidence of diabetes in the human population and the difficulties observed regarding prevention and treatment, there is a need for alternative measures to prevent, treat and control this disease. New measures that can be introduced in the diet without necessitating major lifestyle changes and without incurring in toxicity or adverse effects are particularly needed.